Stoker



Gf R. McGEE Aug. l, A1939.

STOKER Filedl Feb. 19, 1937 3 Sheetg-Sheet 2 Aug. l, 1939.

l 3. R. MOGEE STOKER s'roxnn. George RossAMcGee, Sarnia Township, Ontario,

Canada Application February 19, 1937, Serial lilo. 126,560

1 Claim. (Cl. 11G-45) My invention relates to underfeed stokers for boilers, furnaces and the like.

The objects of the invention, generally, are` to improve on known stokers.

A specific object of the invention is to provide means for automatically and periodically agitating the lower stratum or layer of coal in the hopper, whereby the coal is agitated or loosened and easily feeds bygravity into the charging duct leading to the retort or fire box of the furnace.

Another specic object is to provide an adjustable door over the agitator or bottom of the feed or fuel hopper, whereby the quantity of fuel falling into the charging duct is, regulated.

` ing outwardlm The base is formed witha dat Another specic object is to provide a closed or sealed hopper having means adapted to allow any gas or fumes backing into the hopper to be released to the atmosphere.

Another specic object is to provide a reciprocating feeding ram which may be actuated by a fluid, such as water or oil, for instance.

Another specific object is to provide a scraper or member whichvis actuated by the ram, the free end of the scraper riding upon the wall of the fire box whereby the fuel bed is agitated.

Still another object is to provide a fire box having superposed rings formed to provide tuy res.

In the drawings, wherein like numerals of reference indicate corresponding parts in the various iigu'res,

Figure 1 is a fragmentary, longitudinal section of a stoker constructed in accordance with this invention;

Figure 2 is a fragmentary plan view of Figure 1; A

Figure 3 is a cross sectional view; and,

Figure 4 is a `longitudinal section ofthe fluid 'Dumping 11n-it.

Fig. 5 is a fragmentary side elevation view. of a stoke'r showin'gcertain details,

Fig. 6 is a fragmentary plan view of Fig. 5.

Referring now by numerals to the drawings,V

B indicates the fire box of a fuel burningplant, such as a furnace for instance. The nre box may compriseA a base memberA II, substantially cupshaped, havinga circular extension I2`projectperiperal flange I3 upon which rest a plurality of superposed rings I4 -formed on one face with radially directed passages or air jets I5; The inner facesor edges of the rings may be slanted Q to extend or continue the general inner contour of the base. spaced from the outer edges of the rings is a sleeve or ring it encircling a ring, or

segments of a ring, I1, which in turn encircle, but is or are spaced from, the outer edges of the rings I6, to provide an air space I8 communicating with the air jets I5. The ring IIis formed at the top with a rounded inwardly-directed 5 ange 20 extending to about the inner edge of the uppermost ring I AperturesV ISAthrough the flange I3 of the base permit air to pass into the compartment I8, to be distributed through the l0 H is the fuel hopper, having the slanting bottom wall 2|, top wall ,22, forward wall 23 and box-like forward portion 24. In the bottom wall 2|, and within the box-like portion 24, is a discharge opening 25. The top wall 22 is formed 15 with a charging opening which is closed by a suitable removable lid 26; the box-like portion 2li is preferably provided with an opening which is closed by a suitable lid 21. The lids should preferably be so constructed that the hopper is sub- 20 stantially sealed to prevent escape of gases or fumes whichA may nd their way into the hopper. Suspended adjacent the forward wall 23, by screws 29 and nuts 30. and extending substantially over the entirewidth of the hopper, is avdoor 3l. The position of the lower edge of the door with respect to the bottom Wall 2l denes the throat' or effective opening through which the fuel falls into the bottom of the portion 24.

Arranged below the hopper, and between the. 30

- same and the fire box B, is the fuel charging duct,

, ably circular in cross section, has a flange or connection 36 arranged to lie below the opening 35 25 of the hopper, to receive the `fuel falling out of the hopper or -more particularly the portion 24 thereof.

Fixed to the end of the duct farthest fromA the retort is a casting or head 39 formed with 40 a centrally-located opening to provide a slide bearing for the ram R which must reciprocate within the duct. Suitable packing'is preferably used at 40 betweenthe reciprocable ram and the duct head 39. A Fitted to the outer end of the ram is a head having a tubular sleeve or extension to which-is fittedva cap or closure 46; the cap has a centrally-located opening adapted to slidably receive a pipe or duct Ill. between, and is fixed or fitted to a head 39A at one'endand to a fixed head or block 49. at the other or outer end. y

As the head M moves with the ram R, suitable pacmng -is preferably provided as at 68, that is.

The pipe extends so between the tubular sleeve 45 and the pipe 41. As shown, one or more ports 59 are provided through the pipe or tube 41, adjacent the head 39A of the duct 41. 5 Within the tube 41 and fixed at its ends in the head 39A and the fixed block 49, is a tube or pipe 58. The outer end of the tube 58 is operatively connected, as by a pipe 59, to one port of the pump P (to be described later), and the tube 41 is operatively connected, as by a pipe 60, to another port of the pump. 'I'he pump operates to force a fluid into the inner pipe 58 while withdrawing fluid from the outer pipe 41, and to force the fluid into the outer pipe 41 while withdrawing fluid from the inner pipe 59, alternately. When the fluid is forced into the outer pipe 41, the ram slides in the head 39 away from the ilre box, since the fluid will pass through the orifices 50, into the space between the fixed head 39A and the ram head 44, the iluid in the inner pipe 58 and ram R being withdrawn. When, on the other hand, the fluid isforced into the inner pipe 58, the ram slides in the fixed head 39 toward the re box, the fluid between the fixed head 39A into the outer tube 41.

To the inner end of the ram is pivotally mounted, as at 68A, a bar or scraper 6|, adapted 'to ride or slide at lthe free or inner end on the curved wall of the base of the fire box, so as to agitate the fuel bed by the reciprocating movement of the ram R.

Preferably, a plate 59 is removably secured to the flange 85 of the fuel duct'35, and formed or curved on its lower edge to just clear a portion of the periphery of the ram, the plate providing a wall closing the duct 85 at the hopper discharge outlet 25.

Resting upon the bottom wall 2| of the hopper a, is a plate or false bottom 55, and between this plate and the crank 19 of a shaft 1|, is a connection or link 12, the link through the forward wall'of the hopper portion 24. The link is pivotally connected at one end to the crank 10, as at 19, and pivotally connected at the other end to the plate 95 as by a bolt or the like 18A passing through the curved end 19A lof the link. I'he shaft 1| may be journalled in suitable brackets 15 secured to the forward wall of the hopper portion or extension 24. Fixed to one end of the shaft 1|, adjacent one of the brackets 15, is a lever 15 which is directed downwardly to engage in la recess 11 formed in the horizontal leg of an angle member 18. The horizontal leg of the angle 18 slides on a bar 19 spaced from and arranged parallelly with one of `a pair of channels 80, while the`vertical leg of'the angle 18 slides between thebar 19 and the channel, all as best shown in Figure 3. One end of the angle 18 is secured to the plunger head 44, so that the false bottom of the hopper is actuated back and forth in the hopper by the back and forth movement of the plunger or ram` R. The angle 18 may be connected to the plunger head 44 as by a member 4| ysecured at one end to the angle and secured at the other end to the head 44 as by say, a pin or the like |42. To provide a clearance for the member |4|, the adjacent channel may be notched as at |40.

Air is forced into the base of the retort, from a suitable fan F, through an air duct (or ducts) D opening into the base below the flange I3. The fan may be used to operate the oil pump P actuating the ram R, the fan shaft S having fixed -15 thereon adriving pulley PI.

and ram head 44 passing through the orifices 50 While the invention is not limited to the use of a fluid p ump for operating the ram, there is shown a satisfactory pump or oil feeding system. There is used a reservoir or casing in the bottom of which is stored a suitable volume of oil. Associated with the reservoir, and preferably within the same, is the pump P, (of the plunger type), having a cylinder 85 in which slides a piston 88 actuated or reciprocated by a piston rod 89 eccentrically mounted on a suitably journalled shaft 90. Fixed to one end of the shaftA 90 is a pulley 9|. Between the driving pulley PI on the fan shaft, and the pulley 9|, is tensioned a belt 93, so that the plunger or piston 89 of the oil feeding system is actuated by the fan F. The relative diameters of the pulleys P| and 9| are such that the rotary speed of the latter is considerably reduced. operatively connected with the inside of the cylinder 86, rearwardly of the piston 88, are two ports and 9.8; from the port 95 extends a pipe 91 the open end of which is immersed in the body of oil in the casing, while a pipe 98 extends from the port 99 into a valve casing 99. Within the port 95 is a ball valve |00, the ball resting upon shoulders formed by locally restricting the diameter of this port, so that the ball will operate to stop the ow of oil in one direction, while it will permit of a ow of oil in the opposite direction. Thus, when the piston is advanced toward the ports, oil will be forced into the valve casing 99, while during the opposite travel of the piston, the -ball will operate to prevent oil from being sucked into the cylinder from the valve casing. Supported in a restricted portion of the other port, 95, is a similar ball valve |0|. As the piston travels away from the ports, oil will be sucked into the cylinder from the bottom of the casing, while on an opposite travel of the. piston, the oil in the cylinder is prevented from being forced back into the casing and is forced into the valve casing. From two spaced ports |82 and |98 extend the two pipes 59 vand 60 aforesaid, respectively, so that the inside of the valve casing is operatively connected with the aforesaid pipes 58 and 41, respectively.

Within the valve casing 99 is a loosely mounted valve unit comprising four discs, |95, |09, |01, and |08, rigidly mounted on a rod |99, the rod extending beyond both opposite discs |05 and |08. Arranged, preferably above the bore or longitudinal axis of the valve casing 99, is-an open end cylinder ||0, which is operatively connected to the inside or bore of the valve casing 99 by three spaced ports or passages ||2 and |13; the opposite passages and ||3 open into or communicate with the opposite ends of the valve casing, while the centre or intermediate port ||2 opens into the centre of the casing 99. Slidable in the cylinder I I0 are two spaced discs or pistons ||6 and ||1 fixed to an operating rod ||5 which is operatively connected at one end to the ram head 44, so that the discs or valves i9 and |1 are actuated within the cylinder 0 by the movenient` of the ram R.. The operative connection between rod ||5 and-head 44 may comprise a horizontally arranged block |25 slotted at I2! to receive a roller |21 turning on the free end of the rod. The discs 9 and ||1 are so disposed on the rod |5 that the space or compartment defined by the wall of the cylinder and the two discs is-in operative communication with both of the ports ||2 and H3, or with both ports and ||2, alternately. When in operative communication with both ports ||2 and H9, (See Figure 4), and the piston 88 of the pump is movin the lever 18, that is, the lower end of the lever ing towards the ports 98 and 95, oil from the pump cylinder passing through the ports ||2 and H3, will cause the four discs, |05-|08, to move to the position shown in Figure 4, forcing a stream of oil into the feed pipe or line 59 and into the pipe 58. The ram R will now be travelling toward the retort, the oil in the pipe il passing through the pipe 60, to enter the casing 99 through the port |03 and to discharge into the reservoir through the port |03A. When the discs IIB and have been actuated` to a position shown in dotted lines in Figure 4, the four discs, |05 to |08, will move to a position opposite that shown in full lines in Figure 4, and oil will be forced out of the casing 99 through the port |03, into the pipe 60 and into the pipe or tube M, to move the ram R away from the retort, the oil in the pipe 58 passing through the pipe 59 to enter the valve casing 99'through the port |02 .and be discharged into .the reservoir through the port |02A.

The hopper may be operatively connected to a chimney, as by a pipe (not shown) connected at one end to an opening 24A, so that any fumes in the hopper will be Withdrawn.

Operation' The motor-operated fan which is controlled by 1 a thermostat (not shown) operates to force the required draft to the retort. While the fan'is operating, the fluid or oil pump is operated to force oil into the pipes 41 and 58, alternately, actuating the ram R toward, or away from, the retort, alternately. The movement of the ram toward the retort operates to feed a certain volume of fuel or coal into the bottom of the retort. The movement of the ram operates to slide the false bottom or plate on the bottom wall 2| of the retort to thus further agitate the contens of the hopper. The length of the recess 1l in the angle I8 is such as to provide lost motion will be moved a relatively small distance. The movement of the ram will also actuate the operating link H5 of the pump. In order that the rod IIE may be moved a small distance relatively to that of the ram, the block '|25 is accordingly slotted at |29 to a comparatively long distance. If smoke, for any reason, is drawn into the feed duct 35 bythe outward stroke of the ram R, then the smoke will'nd its way into the hopper, from which it will be exhausted through the vent opening 29A. It will be clearly seen that as the bottom of the hopper is inclined, the false bottom 65 upon sliding back and forth will elevate and lower the connecting rod l2 bodily, at least at the end thereof ,which is connected to the false bottom, and as the rod issubstantially all enclosed within the hopper, the action of the rod will be to further agitate the hopper contents.

What I claim is:

In an underfeed Stoker, the combination of a retort, a fuel hopper having a bottom inclined downwardly toward said `retort. and a vertical wall on its side which is adjacent to said retort,

said bottom .having a discharge opening adjacent the lower end thereof, an agitating member slidably mounted above said bottom, a duct operatively connected between said opening and said retort, a. ram in said duct for feeding fuel into said retort, means for actuating said ram, a ylever pivotally mounted adjacent said wall to oscillate in a vertical plane toward and away from said hopper, means operatively connecting said lever to said ram to osclllate said lever, and a connection pivotally connected between said lever and said agltator,.sald connection passing through said wall and lying substantially entirely within said hopper whereby the movement of said connection in a vertical plane operates to agitate the fuel in said hopper.

GEORGE ROSS McGEE. 

